Title Performance characteristics of para swimmers – how effective is the swimming classification system? Authors Brendan Burkett PhD1, Carl Payton PhD2, Peter Van de Vliet PhD3, Hannah Jarvis PhD4 Daniel Daly PhD5, Christiane Mehrkuehler MSc6, Marvin Kilian MSc7 and Luke Hogarth PhD8 1 Professor of Sport Science, School of Health and Sport Sciences, University of the Sunshine Coast, Sippy Downs, Queensland, Australia. 2 HEAL Research Centre, Manchester Metropolitan University, Crewe, United Kingdom. 3 Medical and Scientific Department, International Paralympic Committee, Bonn, Germany. 4 Postdoc, HEAL Research Centre, Manchester Metropolitan University, Crewe, United Kingdom. 5 Professor in Sport, Faculty of Kinesiology and Rehabilitation Sciences, KU Leuven, Heverlee, Belgium. 6 Masters Candidate, Faculty of Kinesiology and Rehabilitation Sciences, KU Leuven, Heverlee, Belgium. 7 PhD Candidate, Institute of Training Science and Sport Informatics, German Sport University, Cologne, Germany. 8 Postdoc, School of Health and Sport Sciences, University of the Sunshine Coast, Sippy Downs, Queensland, Australia. Key Words (5–8) Swimming Classification, Paralympics, swimming performances, impairments Abstract/Summary [this will be used for indexing services and does not appear with article] Swimming is one of the inaugural sports within the Olympic and Paralympic Games. The key difference between the Olympic and Paralympic games being the classification system. The aim of this study was to investigate how effective the current classification system creates clearly differentiated Paralympic competition classes, based on performance time for all swimming strokes and events. Based on the performance characteristics of swimmers within the current classification system the relationship between impairment and swimming performance is inconsistent, potentially disadvantaging some athletes. Appropriate sports medicine tests are required for the development of an evidence-based swimming classification system. Key Points (3–5) • Paralympic swimming classification began with sports medicine driven medical based system. • The current functional classification system is a swimming-specific system that assigns and integrates athletes with eligible impairments into classes. • Based on performance characteristics of swimmers within the current classification system the relationship between swimming class and performance is inconsistent. Potentially disadvantaging some athletes. • A new evidence-based swimming classification system is currently under development, built on the knowledge from the sport medicine assessment. Introduction The sport of swimming has been part of every Paralympic program since the Games began in 1960 and is one of the most popular sports for para-athletes with a physical, visual or intellectual impairment. For all Paralympic sports, an international classification system determines athlete eligibility and the subsequent ‘grouping’ of athletes for competition. The aim of classification is to achieve fair competition by minimising the impact of an individual’s impairment on the outcome of competition so that sporting ability, skill level and training alone determine success and the final result [1]. Despite this long history of inclusion within the Paralympic Games, questions have often been raised on the effectiveness of the classification system. Indeed, the International Paralympic Committee (IPC) has mandated the development of evidence-based classification systems of classification [1], which highlights the need for a review of the current classification system for swimming. As Paralympic sport evolved from an initial medical rehabilitation program, sports medicine formed the original swimming classification system. This inaugural classification system was based purely on a medical model with athletes ‘grouped’ within five classes of impairment: (i) Athletes with an amputation; (ii) Athletes with cerebral palsy; (iii) Athletes with a spinal cord injury; (iv) Athletes with a visual impairment, and; (v) Athletes with les autres. IPC swimming introduced the Functional Classification System in 1990, which involved two forms of assessment, a sports medicine bench-test that screening the musculoskeletal function of the athlete. The philosophy of this system was to combine the previous medical assessment with sport-specific measures. This assessment involved a modified format of the traditional medical range of movement and strength assessment. The functional classification system is a sport-specific system of classification that assigns and integrates athletes with eligible impairments, predominately physical impairments, into classes in order to maintain equitable and fair competition amongst these athletes [2]. The cumulative score from these equally weighted dry-land measures would determine into which classification the athlete would be placed, as each classification was represented by a specific range of bench-test scores. This test was followed by an in-water assessment, which required the registered IPC swimming classifier to observe the athlete swim in the water, and based on this observation, if necessary, adjust the bench- test score and ultimately the final classification. This combination of medical and sport-specific assessment currently form the activity limitation tests for para swimming. The system has been in place for seven consecutive Paralympic Games from 1992 to 2016, with some modifications over time. The separate classes distinguish between the distinct arm-dominant freestyle, backstroke, and butterfly strokes; the leg-dominated breaststroke; and the individual medley, which includes all four strokes and therefore warrants its own unique classification system. Athletes rated as a 10 on the classification scale (e.g. S10, SB10, SM10) have the greatest function. Function gradually decreases (the scope of the impairment increases) as one moves closer to a 1 rating (S1, SB1, SM1). While the requirement for fairness and equity has been stipulated [3], there has been no quantitative research that has examined if the current classification system results in discrete categories of swimming performance for all events and genders for each class. To date, analysis of Paralympic swimming performance has focused on the factors that contribute to the final outcome, swimming time [4-6]. Therefore, the aim of this study was to investigate how effective the current classification system creates clearly differentiated Paralympic competition classes, based on performance time for all swimming strokes and events. This new knowledge provides the required evidence for the effectiveness of this important Para sport. Methodology The swim time performances for male and female medallist swimmers since the inception of the current functional classification system were obtained from six major competitions, the • 1992 (Barcelona), • 1996 (Atlanta), • 2000 (Sydney), • 2004 (Athens), • 2008 (Beijing) and • 2012 (London) Paralympic and Olympic games. The swim time performance for the male and female Olympic swimmers in corresponding events provided a benchmark comparison. In total, 2,370 race performance times were investigated, with all data downloaded from official, publicly accessible swimming and sporting websites (www.ipc- swimming.org, www.databaseolympics.com). The swim times for male and female medallists in the Paralympic classes and the corresponding swim times for the three Olympic medallists in the following events were recorded: • the 50 m, 100 m and 400 m freestyle, • the 100 m backstroke, • the 100 m breaststroke, • the 100 m butterfly and • the 200 m individual medley. These events were analysed as they were common to both Paralympic and Olympic games. As the data was publicly available and de-identified human ethics approval was not required. To determine if there were clear differences between performances in each class, the mean swimming speeds (m/s) for Paralympic performances were expressed as a percentage of the corresponding Olympic performance. This percentage index allowed for a uniform comparison of race performance between classes, events and genders. Statistical analysis was performed with the Statistical Package for the Social Sciences (SPSS, version 17.0). Normality of distribution of data was confirmed using a Shapiro-Wilk test. The raw swim times and percentage indices of classes were compared for each sex and event using a one way Analysis of Variance (ANOVA) with an alpha value of 0.05. Bonferroni post hoc analysis was used to determine the source of statistical significance when required. A paired sample t-test was used to compare each mean percentage index to a predicted fixed percentage variable. Based on analysis of the percentage indices, this arbitrary fixed variable was set at 85% for class S10 and decreased by 5% for each class down to 45% for class S2. For the classes of visually impaired athletes, (S11, S12 and S13), the arbitrary fixed variable was set at 90% for class 13 and decreased by 5% for each class down to 80% for Class 11. The assignment of this fixed variable was subjective, with the goal of creating equal differences between the classes. Results Of a total of 128 mean raw times across the classes and events, 58 (45%) were found to have no significant difference to their adjacent higher class (Table 1). Of the classes with a physical impairment (S2 to S10) a total of 38 out of 86 (44%) mean values across classes and events were found to have no significant difference in mean